Geographical Distribution of Phase II/III Pharmaceutical Randomized Controlled Trials in Adults With Interstitial...

Pharmaceutical randomized controlled trials (RCTs) are critical for advancing treatments in interstitial lung disease (ILD). This study evaluated the global distribution of pharmaceutical RCTs of ILD and their associations with country-specific features.

Do ILD RCT activities relate to disease prevalence, health care quality, sociodemographic status, and urban population size?

ClinicalTrials.gov was searched from inception to February 2024 for phase II and phase III parallel-group pharmaceutical RCTs of ILD. Trial details and recruiting sites were extracted. For evaluation of relationships with trial activities, country-specific age-standardized prevalence rates for ILD, the Healthcare Access and Quality Index, and the Socio-Demographic Index were obtained from the Global Burden of Disease databases, and urban population percentages were obtained from the World Bank.

A total of 168 RCTs were identified (65% phase II and 35% phase III), which increased over time, with 40% having commenced since 2020. North America participated in the most RCTs (70%), followed by Europe (52%), Asia (42%), Oceania (28%), South America (20%), and Africa (8%). Over the past 2 decades, there was increased participation in ILD RCTs in Asia, South America, and Australia, although recent declines were noted in India, Japan, Russia, and the United Kingdom. The majority of recruiting sites in Africa participated in phase II trials, while most in Asia and South America were involved in phase III trials. For a given country, the numbers of phase II and phase III RCTs conducted were positively associated with the Healthcare Access and Quality Index; the numbers of phase III RCTs conducted and recruiting sites were positively associated with urban population percentages.

Despite expanding global involvement, ILD RCT activities remain concentrated in North America and Europe, with substantial geographical disparity across different regions. Given the increasing ILD disease burden in many countries, ongoing efforts are needed to enhance representativeness of RCT findings and promote their adoption into clinical care.